Shaving head having concentric cutter elements



July 19, 1966 J. VAN DEN DRIEST 3,261,091

SHAVING HEAD HAVING CONGENTRIC CUTTER ELEMENTS Filed July 25, 1964 InnINVENTOR.

JAN VAN DEN DRIEST AGENT United States Patent C) 3,261,091 SHAVING HEADHAVING CONCENTRIC CUTTER ELEMENTS Jan van den Driest, Drachten,Netherlands, assignor to North American Philips Company, Inc., New York,N .Y., a corporation of Delaware Filed July 23, 1964, Ser. No. 384,613Claims priority, application Netherlands, Aug. 20, 1963, 296,894 3Claims. (Cl. 30-43;.6)

The invention relates to a shaving head for use in a dry shavingapparatus comprising a round shear plate having concentric runninggrooves for the cutting members in a single plate, co-operating with acutting head provided with concentric cutter rims united to form anintegral part on a single support.

Such constructions have rarely been employed in practice or they havenot been used at all, since it did not appear to be possible to obtainsuch a co-operation between the races and the cutting members to beproduced in series without excessive cost that, when the shaving head ispressed against the skin a uniform shaving effect is obtained.

The invention has for its object to provide an improvement in thisrespect and is characterized in that the thickness of the upright edgesof the plate, bounding the laminations, measured along a radial linethrough said edges, is more than twice the length of the laminationsbetween said edges, while the cutter rims are centered with respect tothe plate by direct guiding of the cutter support along an annular facewhich is located on the inner side with respect to the outer side of theinner cutter rim.

Consequently, in accordance with the invention there is provided acomparatively great thickness of material in a radial sectional area ofthe portion of the plate where the running grooves are provided, ascompared with the width of said running grooves. With a given diameterof the plate the surface of the shaving operation is smaller than istheoretically possible, but the active shaving surface is neverthelesssufiiciently enlarged in this way to justify the complication involvedin providing concentric running grooves and concentric cutter rims. Inactual manufacture, however, the advantage is obtained that a very smallthickness of laminations is permitted with the said ratio between thethickness of the material and the length of the lamination partsbridging the running grooves while the rigidity remains sufficient.Moreover, the upper surface of the plate, as a whole, maintains such arigidity that the guide of the cutter-rim support, as stated above, canbe provided in the inner part of the plate. This provides a simple andaccurate guide along an annular path of small diameter, which is ofgreat importance for such a choice of the width of the cutting edges ofthe cutters with respect to the width of the running grooves that asmall clearance will be sufficient, which is conducive to the activeshaving surface.

In this case an accurate arrangement of the cutter rims relative to eachother and to the axis of rotation is very important and in anadvantageous embodiment this is achieved in that the inner cutter rim iswelded in the form of a central ring to the bottom of the cup-shapedbody of the outer cutter rim while the inner side of the inner cutterrim is guided along the corresponding side of the associated runninggroove.

In a further embodiment suitable for this purpose a known technique isapplied in which separate cutters are arranged in a rim around the axisof rotation of the cutter head formed by a pressure-cast piece and fixedseparately in the bottom part thereof, while the cutting edges arelocated on the head side of the cutter head.

The known cutter heads of this type have a fairly complicated shape, thecutters having for example the form 3251,91 Patented July 19, lgfifi ofa T, the long limb of which extends through an opening in the cast piecein downward direction, where it is fixed by separate clamping members,the cutter being at the same time urged laterally against a supportingface.

In accordance with the present invention this construction is such thatthe walls of the radial grooves are in direct contact with the lowerparts of the cutters, the lower edges of which bear throughout theirlength on the bottom of the groove, while the cast piece supports, inaddition, a central, upwardly extending centering pin which fits in acentral bore of a shear plate to be arranged over the cutter head.

In this Way the cutters can be rigidly fixed during pressing or castingof the cutter head, while they are held throughout their length both onthe two sides and at the lower edges, whereas the ends of the groovescan be left completely open and no downwardly projecting extension isrequired for fixing the cutters by separate members and to prevent adisplacement in the longitudinal direction. In order to allow suitabletolerances in the disposition in the radial direction, for aninexpensive manufacture, without the need for grinding the end edges ofthe cutters to measure, the centering pin can be formed together withthe casting and be directly provided in the central bore of the shearplate. Thus a radial movement of the cutters in the running groove ofthe shear plate is prevented and a small clearance in the running groovewill suflice.

The cut hairs can be readily conducted away to the hair chamber in anadvantageous embodiment which is characterized in that the radialgrooves are provided in limbs projecting radially from the casting, theupper edges of said limbs extending over part of the bottom surfacebeing bevelled in upward direction towards the grooves.

The invention will now be described with reference to the drawing, whilevarious advantageous aspects thereof will be set forth.

FIG. 1 shows a first embodiment in a vertical sectional view through theaxis.

FIG. 2 shows perspectively in a half sectional view a shear plate in asecond embodiment and FIG. 3 also shows perspectively the support forthe cutter rims, while a cutter removed from the support is shownseparately.

Referring to FIG. 1, reference numeral 1 designates the shear plate and2 designates the support of the cutter rims. It is shown that on thebottom 3 of said support, which has the shape of a cup or dish and withwhich the outer cutter rim 4 is integral, there is welded a central ring5, which holds the inner cutter rim 6. The inner side 7 of the cutterrim 6 is guided along the inner side 8 of the corresponding runninggroove 9.

Viewing a portion of the cutting head indicated by the arrow P, goingthrough the ends of the cutters and the boundaries of the runninggrooves, it will be apparent that there is supporting material on eitherside of the laminated parts 10 which bridge the running grooves. Theoverall width of the two running grooves in a practical embodiment is 3mms. and the length of the part P is about 8 mms.

In the embodiment shown in FIGS. 2 and 3 the laminated shear plate 11has two concentric running grooves 12 and 13, in each of which a cutterrim is adapted to rotate.

The two rows of cutter rims are obtained (see FIG. 3) by fixing a seriesof cutter plates 14 in a cutter head support 15, each cutter platehaving the shape of a U, the ends of the legs 17 and 18 form the cuttingedges, while the ridge or the web 16 is fixed in one of the grooves 19in support 15.

The upwardly projecting centering pin 21, which is integral with thebottom of the cutter head, is journalled, after mounting, in the centralbore 22 of a bearing sleeve 3 23, the latter being housed in the centralopening shear plate 11.

The radial grooves 19 are provided in legs radially projecting from thesupport 15, said legs bearing the reference numeral 24; the upper sides25 of said legs are projected over a given distance above the topsurface 20 of the support 15. On either side of the cutter these sidesare bevelled in upward direction, so that the sloping faces 26 and 27are formed. The cut hairs can therefore be readily conducted awaybetween the legs 24 towards the hair chamber below the support 15.

From the cutter shown separately in FIG. 3 it will be seen that the Web16 of each cutter is provided with openings 28 and 29 so that in thepressure or spray casting process for the cutter head support 15 amaterial connection is obtained between the sides of the grooves acrosssaid openings. The manufacture may be carried out by means of anextrusion process and the casting may consist of so-called sprayedaluminum. The central pin 21 may be made of steel and may be cast at thesame time of a sleeve of steel or brass which may he slipped onto analuminum pin which is integral with the support 15.

In FIG. 3, the broken lines indicate in the separate outter 16 that thelegs of the U-shaped cutter may be bent over to one side, so that asharp cutting angle is obtained after horizontal grinding.

What is claimed is:

1. A shaving head for use in a dry shaver comprising an invertedcup-shaped, apertured shear plate having conof the centric annulargrooves therein and a central bore, a 30 rotary cutter support having atleast two concentric rings of cutter blades, each of said blades beingrotatable in the grooves of said shear plate adjacent to said apertures,the thickness of the lateral walls of the shear plate surrounding saidgrooves being more than twice the thickness of the portions of the shearplate directly above said grooves, said rotary cutter support beingprovided with an upwardly projecting centering pin fitted in saidcentral bore, and a plurality of additional grooves extending radiallyfrom said rotary cutter support and each adapted to have secured thereinat least one of said cutter blades.

2. A shaving head for use with a dry shaver as claimed in claim 1wherein said cutter blades are U-shaped, with the ends of said legsforming the cutting surfaces.

3. A shaving head for use with a dry shaver as claimed in claim 1further comprising bevelled side portions adjacent to each of saidadditional grooves for permitting the cut hair which accumulates thereonto further fall by gravity away from said rotary cutter support.

References Cited by the Examiner UNITED STATES PATENTS 2,119,021 5/1938Moskovics et a1 30--41.5 2,220,800 11/1940 Jepson 30-354 X 2,238,2784/1941 Moskovics et al. 30354 X 2,282,539 5/1942 Bahr 3043.6 2,575,74111/1951 Abrams et al 3034.1 2,616,168 11/1952 Dankers 3043.6 2,632,9483/1953 Konrad 30-43.6

FOREIGN PATENTS 1,088,648 9/ 1954 France. 571,355 1/1958 Italy.

' WILLIAM FELDMAN, Primary Examiner.

MYRON C. KRUSE, Examiner.

1. A SHAVING HEAD FOR USE IN A DRY SHAVER COMPRISING AN INVERTEDCUP-SHAPED, APERTURED SHEAR PLATE HAVING CONCENTRIC ANNULAR GROOVESTHEREIN AND A CENTRAL BORE, A ROTARY CUTTER SUPPORT HAVING AT LEAST TWOCONCENTRIC RINGS OF CUTTER BLADES, EACH OF SAID BLADES BEING ROTATABLEIN THE GROOVES OF SAID SHEAR PLATE ADJACENT TO SAID APERTURES, THETHICKNESS OF THE LATERAL WALLS OF THE SHEAR PLATE SURROUNDING SAIDGROOVES BEING MORE THAN TWICE THE THICKNESS OF THE PORTIONS OF THE SHEARPLATE DIRECTLY ABOVE SAID GROOVES, SAID ROTARY CUTTER SUPPORT BEINGPROVIDED WITH